I modded my door key fob that is used to enter our building.
Since a couple of weeks, we have new keys for our university buildings, namely an RFID keyring fob. However, they are rather ugly, and by the philosophy that we should strive for beauty, I decided to do something about it!

First, the results

Left 'before', an ugly black/gray, plastic, hard thingy. Not a good way to start your day. On the right, a nice soft pink/blue elephant. Now that will surely cheer you up! (Pictures by Erwin.)